From patchwork Thu Aug 11 18:52:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Koller X-Patchwork-Id: 12941699 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B7EDC25B0C for ; Thu, 11 Aug 2022 18:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235976AbiHKSwV (ORCPT ); Thu, 11 Aug 2022 14:52:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235967AbiHKSwR (ORCPT ); Thu, 11 Aug 2022 14:52:17 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FC969DF98 for ; Thu, 11 Aug 2022 11:52:16 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id z5-20020a056a001d8500b0052e691eed53so7916450pfw.13 for ; Thu, 11 Aug 2022 11:52:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=zz99fKzwjwDHJo8VLz/7LS0wHhldAxFtS0b0KytwMEA=; b=mMsWaCnsqnOEQ6Bvki66q5wsRB1x/slSTddPfkvkrLtK6Q+LOEU1HNlHVTL8/bp1Iw Ji1uYYaunHXFkpuA+lePaCSi8rwJBS/RA8E8gCrGQ7ZZ2s2notMohma6oUFzZeFpK8li KE3JiZwdZLer9YdEAbUC0Z09HDEFBLkDSdNDttDL7RjedJGa5GTryHXGXXYyr+Xy+BG8 kNFXct3+hZh8ApS+9newCGooHT4N9OsiMyyasWVx4OnAvg9mYu77X4T9kUDnmM2Rjfw2 GA5GNrNJOVXo8I34xra58Kt666Cpz6ss7J0gOLTiPxVIEEok84r+SiqjdTNtSh4SRmcJ x/Kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=zz99fKzwjwDHJo8VLz/7LS0wHhldAxFtS0b0KytwMEA=; b=YY2BkSLyI4cG1MQAcIkAF/0u9AQrndP6dXFS19Ykpv00FdxrvligdT63pz/x/Zb9ox 4MwLCZCcV0e97gPmbrdA/0RLgnHJM1f/+OAK6sdDO58sXZGWwGINq4H9jB/0rDSs7E2n 0kNb7vdj/D9wvRPurAsz3m3hHKbWo5wf8FXFBnOydUEg+fsoOJNhcaoQfVfyftfE4tkp mNuV9dvsK00siFd0wKj/wAexLQL60OQV9L9cpBhAbJknu4tqafyMJ5aA2rh61DgJeKpe Ttq+GoxOXCSw8IcQE9nTibPtREZpzh/qjztDhIMDzJd8MzR5hYcmXAFcOG+71OCwuFYD Xkow== X-Gm-Message-State: ACgBeo2kCbXE3OSJuhhjaSaWCZbH+3AU3WWwFCNvZ0ye16bK9QYinRsZ Ba+0acINowcGJenM+6oe51mb971M1oFlPOZhQBc0XV9Y9V1elOllH2YtGXEmsL3eKmVYDo1qLXX b/Bf74F0y27LCRYAmDnu5vh4L7VUJxqnWH4k15tM5HO4v7XK195pbP1KuLa5Fcdw= X-Google-Smtp-Source: AA6agR6KCV4zKclcwL7i7wND5hfdvI19kKOD0HMnJIDp9WuoEU90pLaAs38vmeyM2AskMn48YMCmelVVkyiWvw== X-Received: from ricarkol2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:62fe]) (user=ricarkol job=sendgmr) by 2002:a17:90a:9ce:b0:1f3:c90:6e99 with SMTP id 72-20020a17090a09ce00b001f30c906e99mr10125701pjo.211.1660243935689; Thu, 11 Aug 2022 11:52:15 -0700 (PDT) Date: Thu, 11 Aug 2022 11:52:07 -0700 In-Reply-To: <20220811185210.234711-1-ricarkol@google.com> Message-Id: <20220811185210.234711-2-ricarkol@google.com> Mime-Version: 1.0 References: <20220811185210.234711-1-ricarkol@google.com> X-Mailer: git-send-email 2.37.1.559.g78731f0fdb-goog Subject: [kvm-unit-tests PATCH v4 1/4] arm: pmu: Add missing isb()'s after sys register writing From: Ricardo Koller To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, andrew.jones@linux.dev Cc: maz@kernel.org, alexandru.elisei@arm.com, eric.auger@redhat.com, oliver.upton@linux.dev, reijiw@google.com, Ricardo Koller Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org There are various pmu tests that require an isb() between enabling counting and the actual counting. This can lead to count registers reporting less events than expected; the actual enabling happens after some events have happened. For example, some missing isb()'s in the pmu-sw-incr test lead to the following errors on bare-metal: INFO: pmu: pmu-sw-incr: SW_INCR counter #0 has value 4294967280 PASS: pmu: pmu-sw-incr: PWSYNC does not increment if PMCR.E is unset FAIL: pmu: pmu-sw-incr: counter #1 after + 100 SW_INCR FAIL: pmu: pmu-sw-incr: counter #0 after + 100 SW_INCR INFO: pmu: pmu-sw-incr: counter values after 100 SW_INCR #0=82 #1=98 PASS: pmu: pmu-sw-incr: overflow on counter #0 after 100 SW_INCR SUMMARY: 4 tests, 2 unexpected failures Add the missing isb()'s on all failing tests, plus some others that seem required: - after clearing the overflow signal in the IRQ handler to make spurious interrupts less likely. - after direct writes to PMSWINC_EL0 for software to read the correct value for PMEVNCTR0_EL0 (from ARM DDI 0487H.a, page D13-5237). Reviewed-by: Alexandru Elisei Signed-off-by: Ricardo Koller --- arm/pmu.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arm/pmu.c b/arm/pmu.c index 15c542a2..4c601b05 100644 --- a/arm/pmu.c +++ b/arm/pmu.c @@ -307,6 +307,7 @@ static void irq_handler(struct pt_regs *regs) } } write_sysreg(ALL_SET, pmovsclr_el0); + isb(); } else { pmu_stats.unexpected = true; } @@ -534,10 +535,12 @@ static void test_sw_incr(void) write_sysreg_s(0x3, PMCNTENSET_EL0); write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); + isb(); for (i = 0; i < 100; i++) write_sysreg(0x1, pmswinc_el0); + isb(); report_info("SW_INCR counter #0 has value %ld", read_regn_el0(pmevcntr, 0)); report(read_regn_el0(pmevcntr, 0) == PRE_OVERFLOW, "PWSYNC does not increment if PMCR.E is unset"); @@ -547,10 +550,12 @@ static void test_sw_incr(void) write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); write_sysreg_s(0x3, PMCNTENSET_EL0); set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); + isb(); for (i = 0; i < 100; i++) write_sysreg(0x3, pmswinc_el0); + isb(); report(read_regn_el0(pmevcntr, 0) == 84, "counter #1 after + 100 SW_INCR"); report(read_regn_el0(pmevcntr, 1) == 100, "counter #0 after + 100 SW_INCR"); @@ -618,9 +623,12 @@ static void test_chained_sw_incr(void) write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); + isb(); + for (i = 0; i < 100; i++) write_sysreg(0x1, pmswinc_el0); + isb(); report(!read_sysreg(pmovsclr_el0) && (read_regn_el0(pmevcntr, 1) == 1), "no overflow and chain counter incremented after 100 SW_INCR/CHAIN"); report_info("overflow=0x%lx, #0=%ld #1=%ld", read_sysreg(pmovsclr_el0), @@ -634,9 +642,12 @@ static void test_chained_sw_incr(void) write_regn_el0(pmevcntr, 1, ALL_SET); write_sysreg_s(0x3, PMCNTENSET_EL0); set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); + isb(); + for (i = 0; i < 100; i++) write_sysreg(0x1, pmswinc_el0); + isb(); report((read_sysreg(pmovsclr_el0) == 0x2) && (read_regn_el0(pmevcntr, 1) == 0) && (read_regn_el0(pmevcntr, 0) == 84), @@ -821,10 +832,14 @@ static void test_overflow_interrupt(void) report(expect_interrupts(0), "no overflow interrupt after preset"); set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); + isb(); + for (i = 0; i < 100; i++) write_sysreg(0x2, pmswinc_el0); + isb(); set_pmcr(pmu.pmcr_ro); + isb(); report(expect_interrupts(0), "no overflow interrupt after counting"); /* enable interrupts */ @@ -879,6 +894,7 @@ static bool check_cycles_increase(void) set_pmccfiltr(0); /* count cycles in EL0, EL1, but not EL2 */ set_pmcr(get_pmcr() | PMU_PMCR_LC | PMU_PMCR_C | PMU_PMCR_E); + isb(); for (int i = 0; i < NR_SAMPLES; i++) { uint64_t a, b; @@ -894,6 +910,7 @@ static bool check_cycles_increase(void) } set_pmcr(get_pmcr() & ~PMU_PMCR_E); + isb(); return success; }